1. Field of the Invention
The present invention relates to a lace provided with a tubular lace body.
2. Description of the Related Art
Conventionally, as to a lace which needs to be pass through a hole for fixation, a lace, where its core is made of a linear material having elasticity such as a rubber, the outer periphery of the core is covered with fiber, and the fiber portion has knobby portions for hooking into holes of a lace-up shoes, thereby being fixed without lacing, is well-known.
The knobby portions are braided so as to hook the hole after passing through the hole of the lace-up shoes, and can freely vary its diameter depending on the tension put on the lace. Therefore, the lace has a configuration, where a plurality of knobby portions, of which ends are fixed by the rubber of the core, and the core which is inelastic (flexible) and not fixed, are braided and placed. When a tension is put on the core of rubber, the rubber portion extends and the distance between the ends extends, so that the core of the knobby portion becomes flat, and the diameter becomes smaller.
Moreover, when the tension is not put on the lace, the rubber portion becomes normal length, and the distance between the ends also becomes normal, so that the shape of the knobby portion is restored to be original, and the diameter becomes greater.
Thus, it is possible to control variation of the diameter of the knobby portion by the tension put on the lace, so that the shoe lace which does not loosen without lacing can be made as described above.
For example, the Japanese Patent No. 3493002 discloses such lace provided with knobby portions.
3. Related Art Documents    Patent Document 1: Japanese Patent No. 3493002
However, in the above technology, the both ends of the inelastic knobby portion are fixed to the rubber core, so that the rubber portion cannot extends under high tension. The reason is that the knobby portion is braided by the inelastic fiber and the rubber portion is fixed by the inelastic.
Moreover, the rubber portion corresponding to the core of the knobby portion repeats extension and shrinks in response to the high tension.